the foil has two sides......if you put it from the ''dull' side then your plants are ok.....if you put it from the ''shiny'' side then you face a possible hazard as you can crate in this way hot spots that can burn the leaves.....it is ok to blow the fan directly on to your plants.....the air flows towards the plant and shakes the leaves,stems, the plant altogether.....for every action there is a reaction.....action:air shakes the plant (not too much though) , reaction:the plant grows healthier, stronger, more compact in order to be able to resist more powerful winds in the future....the root system is healthier and bigger in order to support such a structure.....i am not an expert, i am in my first grow as well.....have done all these and within 6 weeks from seed i have seen growth of 2 ft in 4 out of 9 plants that i have......also....your temp is optimal.....optimal temp for veg is between 27C-30C....the humidity 40% that you have can be a bit higher for veg.....for flowering optimal temp is 20C-25C and humidity 30-40%.....the lights you have are good (i have only a 400 HPS).....again you can approach them closer to the plants if you put the fan blowing directly to the top of the plants......